Soil adhering to disk blades leads to large accumulations of soil and crop residue between the disk blade and boot or scraper. This is known as “plugging” and requires the machine operator to stop and manually remove the debris before continuing. Previous attempts to address this problem included changed scraper shape, increased spring force between scraper and blade, and “jack bolts” to force contact between scraper and blade. Scraper shape alone has not been successful in eliminating the plugging. Greater spring force and jack bolts have been marginally successful but at the cost of increased wear, component breakage, and disk blade stoppage in loose, dry soil. In addition, the machine may be used to apply anhydrous ammonia (NH3) which aggravates the problem because wet soil will freeze and adhere to the disk blade. All known disk blade scraper designs have the limitation that they only match the disk blade shape in one condition, typically flat disk blade without soil pressure loading. The disk blade is typically placed at an angle relative to the forward travel direction of the seeding machine, and soil pressure during operation deflects the disk blade, resulting in a gap between the disk blade and scraper allowing soil to adhere to the blade (see FIG. 1 for exemplary deformation of an opener disk blade).
What is needed in the art is a scraper assembly which is less prone to plugging and better follows the contour of a disk blade when deflected during operation.